Category: Sustainability Psychology

Even as scientists consciously rejected religion as a basis of natural knowledge, they held on to certain cultural presumptions about what kind of person had access to reliable knowledge. One of these presumptions involved the value of ascetic practices. Nowadays scientists do not live monastic lives, but they do practice a form of self-denial, denying themselves the right to believe anything that has not passed very high intellectual hurdles.

What is normal? Normal is getting dressed in clothes you buy for work, driving through traffic in a car that you are still paying for in order to get to the job that you need so that you can pay for the clothes, the car, and the house that you leave empty all day in order to afford to live in it.

When I exercise, I choose to run outside. It could be 100 degrees or 35 below zero and I will still lace up and hit the pavement. I avoid gyms because I am convinced that regular time spent outside is good for me. When I sit inside or stand behind a counter all day, I cringe at the thought of wasting even 30 minutes of my breath in a gym; I gulp my breaths, and the finest air is outside.

That being said, I’m not a hardcore outdoors person. I like living in cities with lots of people, opportunities, ideas and 10pm happy hours. I have no desire to live on a farm. I take to heart the words of Jim Gaffigan, who quips, “The happiest camper is the one leaving the campsite.” When I’m outdoors, I love the sights and smells of plants, animals and freshwater, but camping to me feels a lot like chores during valuable free time. I escape outside, but I live in a city.

There’s something to be learned from this feeling toward natural environments. For much of human history, our ancestors lived and died surrounded by green environments. Our bodies and our minds are built from copies of their surviving genes, so we are prepared for those same kinds of environments. The steel and concrete worlds that many of us inhabit now are mismatched with our tendency toward biophilia, or our affinity to life in its natural form.

Now, without forsaking civilization for the life of a hunter-gatherer, or without tearing down all the buildings and ripping up the roads, how can we use this supposed affinity for green to better our lives? Is it possible to both live in a city and experience the natural environment?

I think so. Live near green space. Fight for its development or against its destruction. Here’s why.

New research from Mathew White and his colleagues sheds light on the psyvchological benefits of green space. Generally, these researchers are interested in population level estimates of well-being. Because much research focuses on factors associated with negative outcomes, these researchers wanted to know what is associated with flourishing. They asked a simple question :

Does living near urban green space contribute to psychological well-being compared to other factors?

Cross-sectional research (i.e., snapshots of a population at one time) suggests that it does, but that research is confounded by time-stable characteristics, namely, personality. It could be that happy people move to areas where there is a lot of green space. To control for this, White and company analyzed longitudinal data of over 10,000 people from an 18-year panel survey, the British Household Panel Survey. They were able to compare the self-reported psychological health of the same people at different points in time alongside other known contributing variables such as education, employment, marriage and local crime.

For 10,000+ people in England, the average score on the GHQ was 1.92 with a margin of error of ± 0.02 points. For every 1% increase in green space, there was a 0.0043 decrease in GHQ.

The average response for life satisfaction was 5.2 with a margin of error of ± 0.01 points. For every 1% increase in green space, there was a 0.0043 increase in self-reported life satisfaction.

To put this into perspective, people in this population lived in areas composed of, on average, 64% green space. Living in areas composed of 81% green space (1 standard deviation above the average) compared to living in areas composed of 48% green space (1 standard deviation below the average) was associated with a 0.14 point reduction in scores on the GHQ and a 0.07 increase in life satisfaction.

The benefits of the chosen analysis allowed for comparison to other factors associated with mental health and well-being. Using the same comparisons between living in areas with green space 1 standard deviation above and below the average amount, the reductions in scores on the GHQ were:

35% as large as those associated with being married

12% as large as those associated with being employed

The associated increases in life satisfaction were:

28% as large as those associated with being married

21% as large as those associated with being employed

These effects aren’t large, but they are meaningful considering that no correlations with were found between the GHQ nor life satisfaction and living in areas with lower crime rates or in households with higher incomes.

Since not all potentially influential factors were controlled for in the analysis, causality cannot be assumed. These finding should be considered in the context of other research on the effects of green space on well-being. I’ve written on some of this research before, and I hope to tackle more of it in the future. Visit here for another great blog on this topic.

‎”…centuries of human habitation have nibbled away not only at the earth but our perception of what constitutes nature. When we do not miss what is absent because we have never known it to be there, we will have lost our baseline for recognizing what is truly wild. In its domestication, nature will have become just another human fabrication6, 13.”

We can’t measure darkness. Darkness is the absence of something. Light, however, can vary in intensity, from low to high or dim to bright. It’s when light isn’t there that you have darkness. But the light gradient that we can imagine is limited to the light that we’ve already experienced. Given the brightest light we’ve ever seen, we can imagine dimmer light, and even no light—but brighter light than the brightest? In the same vein, when we think about what constitutes a diverse, natural setting, we often fall into the same problem with referencing. The baselines we use, to scale a lush, beautiful, natural environment against an grave, polluted one, are biased by the ‘nature’ that we’ve experienced. One person’s green could be indiscernible to another’s, like distinguishing objects in a dark room when you’ve just come in from outside. It’s possible that if the people living during the slightly younger earth could see us now, they’d need a lamp to cut through the darkness we’ve enshrouded ourselves in.

Houston engulfed by smog

With every passing year, more people are living on the planet, using more resources in turn. The water gets dirtier; the air is more polluted; the soil becomes less fertile; more toxic waste is produced and displaced; and deforestation and other means lead to the extinction of more than 27,000 species annually13. What’s additionally problematic is that what is ‘normal’, in terms of these finite, natural resources, changes with each passing generation. Peter Kahn, Jr.14,15,13 called this phenomenon environmental generational amnesia, or “the shifting baseline problem.” An example of this is suggested by interviews in one study of African American children living in inner city Houston. Essentially, the kids understood the concept of air pollution, but not that Houston might have a problem with it (it’s one of the most polluted cities in the country)12,13. Long-term residents in Los Angeles experienced a similar referencing dilemma with smog and their health4,5,13. Sure, smog is bad; dirty is worse than clean, and more resources is better than less. But who’s to say that less ‘nature’ is bad? Can’t we function well without nature, or even find a substitute? After all, we have technology!

Well, to say less nature is bad, we’d first have to show that nature is good. There’s great evidence to suggest that interacting with nature (e.g., plants, animals, water bodies, sun, sky, etc.) is beneficial to peoples’ well being2, 8, 14, 22, 13. Still, children are increasingly coming to understand nature more through T.V. and the Internet than through the real thing15,13. You might say that perhaps nature via technology is just as good. Have you ever tended a real garden9,11,13 or shot a real bird19,13 over the internet? Additionally, there is certainly evidence that points to the psychological benefits (e.g., stress recovery, stress prevention) of pictures10, 16, 17, 13 and videotapes18,13 of nature. One group of researchers streamed nature scenes on plasma TV’s installed in an office building, and people reported increased psychological well being, cognitive functioning, and connection to the community and to nature7, 13. They called these T.V.’s “windows to the outside.” Alas, though self-reported feelings are useful (we can often rely on people to portray their own subjectivity), good scientists try to tease out how these feelings map onto other measures of psychological and physiological states. We can ask, “Can nature T.V. benefit people in ways similar to real nature? What can we manipulate and what can we measure to explore a difference if it’s there?”

Some really clever researchers at the University of Washington in Seattle asked these same questions. They brought in 90 undergraduate students (half male, half female) to complete a series of cognitive tasks. Participants entered an office and waited for 5 minutes. They then completed a proofreading task, a “name-a-droodle” task (what would you call this ambiguous figure?), an “invent-a-droodle” task (Hey, make your own ambiguous figure!), and a “tin can unusual uses” task (what could you use this can for?). Finally, they waited again for another 5 minutes.

What’s clever about it? One-third of the participants completed the tasks in a room with a blank wall, and another third did so with the window open, overlooking a nature scene with a fountain area that “extended to include stands of deciduous trees on one side, and a grassy expanse that allowed a visual ‘exit’ on the other13.” Here’s the interesting condition: the last third of the participants could view the same nature scene, but on a 50-inch plasma television. What did they measure? Heart rate, looking behavior, weather conditions and lighting. Every new task was preceded by a researcher’s personal instructions, a social interaction which provided a low-level stressor (heart rate increases slightly) that could be used to assess heart-rate recovery. There was also a camera, time synchronized with the heart-rate monitor, that was focused on the participants’ faces (how often do they look, and for how long?). They controlled for the outside weather conditions, the lighting on the work surface, and even the distance between the participant and the “window”, glass or plasma. However, because it took so long to install and uninstall the television in the window, the conditions were less than perfectly randomly assigned.

The researchers hypothesized that the rate of heart-rate recovery (after the social interaction) would be greater in the glass window condition compared to the blank wall. They also hypothesized that the longer participants looked at the glass window, the greater the rate of heart-rate recovery. Whether the plasma television effected heart-rate recovery differently than the wall, or differently relative to the time spent looking at it compared to the glass window, was essentially up for grabs.

What did they find? First, heart rate recovery was significantly more rapid in the glass window condition compared to the blank wall, whereas there was no such difference comparing the plasma T.V. condition to the blank wall. Surprisingly, participants looked at the glass window just as often as the T.V., but they looked at the glass window longer. The longer they looked at the glass window, the more rapid the participants’ heart-decreased. This was not the case for duration of looking at the plasma T.V. What’s more is that these findings are significant when controlling for the light on the desktop and the weather conditions outside.

What’s happening at the levels of brain and body when our heart-rate changes? I think that first we should understand how neurons can help communicate information between brain and body. The nervous system is a closed loop of neurons involved in sensation, decision and reaction20. When any kind of receptor organ is stimulated, information is carried via afferent neurons (mediated by interneurons) from that organ to the brain for decision processing, and then back again via efferent neurons to the receptor organ20. How that organ reacts depends on the brain’s ‘decision.’ Afferent neurons are also called sensory neurons, and efferent neurons are also called motor neurons. It’s efferent (motor) control of the cardiovascular system that we’re interested in. Specifically, we want to know about what is responsible for increasing and decreasing heart rate.

The “pace” of our heart rate is modulated by the sinoatrial node (S-A node) in the right ventricle of the heart1. This node is a specialized clump of cells that initiates action potentials for rhythmic beating. The S-A node is our receptor organ of interest. The sympathetic nervous system (SNS), a division of the autonomic nervous system, is responsible for increasing our heart rate (think fight or flight), whereas the parasympathetic nervous system (PNS), the other division, is responsible for maintaining it and decreasing it (think rest and digest). Heart rate is actually kept at a baseline rhythm by the PNS, which innervates the S-A node by the vagus nerve. It is when PNS activity increases that heart rate slows, and when it decreases that heart rate will speed up21. The SNS also innervates the S-A node and increases heart rate through the b1 adrenergic receptors1.

Where is all of this activity originating? Well, the medulla oblongata is like the “cardiac center” of the brain3. If I were to say that the medulla is a ‘center’ making ‘decisions’, I mean that certain parts of the brain (like the medulla) specialize in specific functions (like regulating heart rate), and these specialized areas generate output information based on information that they have received from a multitude of sources (e.g., other brain areas, sensory nerves). The neurons for the vagus nerve efferents (motor, leaving the brain) are found in the dorsal motor nuclei of the vagus in the dorsal aspects of the medulla. Some sympathetic activity comes from the spinal cord, but those efferent neurons are controlled by neurons originating in the dorsolateral reticular formation of the medulla3. When activity increases in them (action potentials), adrenergic activity increases, increasing arterial pressure. These are known as pressor areas, whereas the opposite, depressor areas, are located medially (toward the center) and ventrally (toward the bottom) from the pressor areas. Exciting these areas decreases adrenergic activity, decreasing arterial pressure. The pressor area and the dorsal motor nuclei of the vagus nerve together make up the cardiovascular ‘center3.’ As you can see, even the center’s ‘decisions’ are the product of other inputs.

What this research I’ve described suggests is that something about viewing natural settings can slow down our heart rate. I don’t think that it’s too far-fetched to say that this something is providing input to the cardiovascular center in the medulla that, in turn, ‘decides’ to pump the breaks on our heart rate. Contrary to past claims, it doesn’t look like nature on the tube can provide the same physiologically restorative effect.

The authors noted that their findings speak to a larger problem: the world’s natural resources are quickly disappearing, and new generations are using a degraded version of the world to form their standards of what’s natural, and what’s deplete. We’re forced to keep asking ourselves, “Can we substitute, and is the substitute just as good?” Yes, as population bourgeons, and we’re faced with new problems (i.e., space, food, water), sometimes we have to make due with what is good enough. We’ll adapt, right? Absolutely, but as the authors somberly suggest, “it is important to address the issue of whether such adaptations are not just different but impoverished from the standpoint of human functioning and flourishing…13.” How can we understand the refreshing benefits of a healthy and diverse ecosystem, when we’re walled in by steel and concrete? How can we understand the broad illumination of light, when we’re surrounded by darkness?

A few weeks ago, I was able to embark on something very special, yet essentially cost-free: after lunch, a few good friends and I went for a walk around Lake Harriet. Although I spend a lot of time outside running for cross-country and track & field, rarely do I set aside the time to experience the outdoors at a relaxed, more mindful pace. It doesn’t matter how fit I get; in my mind, I can just absorb more from my surroundings while walking than while running. On this Saturday morning stroll, I delighted in noticing what the trees looked like, how blue the sky was, and how placid the frozen lake stood. I guess more than anything though, I noticed the words shared with my friends. My thinking and my responding seemed clearer and easier; I could more easily listen to and parse through their sentences, take more pause in contemplating and mouthing my own, and I could just simply reflect on our ideas, both their nuances and their larger scopes.

It would seem that there is something about walking in nature that is influencing how I think, or, more specifically, how I pay attention. Researchers as the University of Michigan would certainly think so. In one study, they were interested in the differences in the restorative affects on cognition in ‘natural’ settings versus urban settings. Their hypotheses were centered around Attention Restoration Theory (ART), which builds off research differentiating involuntary attention from directed attention—your attention is either grabbed by stimuli (involuntary), or you focus your attention in a top-down fashion (directed). The theory goes like this: inherently fascinating stimuli grab your attention involuntarily, yet modestly, so your directed-attention mechanisms can work alongside the attention dedicated to the bottom-up stimuli. In contrast, more intense stimuli grab your attention dramatically, so your directed-attention mechanisms have to compete with the stimuli themselves. If you want to use your directed-attention for cognitive tasks, it follows that you would be better suited in an environment with stimuli that give your attention room to work, rather than compete for your cognitive resources. The researchers argue that this is the difference between ‘natural’ environments and urban ones.

Thirty-eight University of Michigan students participated in the first experiment of two. Before the manipulation, participants filled out a scale to assess their mood, then they performed what’s called a backwards digit-span task; basically, they heard number sequences of varying length and they had to repeat them backwards in order—this a solid measure of directed-attention. To tax directed-attention even further, participants took a directed-forgetting task as well, in which they are presented with words to either remember or forget, and then they are asked to recall every word presented. This extra cognitive-fatigue was induced in hopes of making the environmental manipulation more sensitive to differences in performance.

Next, half the participants took a walk through the Ann Arbor Arboretum, and half walked through downtown Ann Arbor. Essentially, participants were walking by lots of pretty tress, or by heavy traffic and boring buildings. When they got back, they retook the backwards digit-span task and the mood scale, and then they answered questions about their walk. They came back a week later to do it all again, except they walked in the other condition’s route. Performance on the backwards digit-span task improved only in the ‘nature walk’ condition, controlling for the order of the walk conditions, mood, and even different weather conditions.

In the second experiment, 12 University of Michigan students took the mood scale and performed the backwards digit-span task, but they also completed the Attention Network Task (ANT). Basically, participants respond to the direction of a ‘target’ arrow on the middle of the screen (which way’s it pointing?), and performance reflects three components of attention: alerting, orienting, and executive. In the alerting component, a central cue (an asterisk) indicates when the target arrow is going to appear. Performance is measured by the difference in reaction time (RT) and in accurate identification of the arrow’s direction (ACC) when participants get the cue, or not. The orienting component measures differences in RT and ACC when participants get a cue indicating where the arrow will be on the screen (sometimes the target’s on the top, or the bottom), or not. Finally, the executive component measures differences in RT and ACC when the screen has either congruent (same direction) or incongruent (opposite direction) ‘flanking arrows’ next to the center target arrow.

After this battery of tasks, half the participants looked at ‘nature’ pictures (Nova Scotia!), and the other half looked at urban pictures (Ann Arbor, Detroit, Chicago). Then, they rated how much they liked the pictures, followed by another backwards digit-span task, a mood scale, and the ANT. They came back a week later and did it all again, but they looked at the other pictures. Improvements on the ANT and the backwards digit-span task were significant only after viewing ‘nature’ pictures, and only the in the executive component of the ANT. The researchers noted that if orienting and alerting components of the ANT would have improved significantly, increases in motivation or in effort, instead of attention, could have explained ‘nature’s’ influence on performance.

Alas, this is a neuroscience blog, not a cognition blog; where are they fMRIs and the rat models!? It’s actually a little difficult to find direct research on the neuroscience of interacting with nature. Unfortunately, fMRI studies require a little more persuasive, academically-sexy grant proposals than do cognitive and social psychology studies (something about expensive, intricately calibrated, high-powered magnets), so researchers have yet to stick nature walkers in an MRI machine and publish a paper about it. However, since most, if not all, cognitive measures have been studied both behaviorally and neurally, we can look at the neuroscience of ‘nature’ indirectly. In the case of the Michigan study cited above, the independence of the attention components measured in the Attention Network Task have been validated with neuroimaging. In one such study at the Weill Medical College of Cornell University, sixteen right-handed adults (mean age of about 27, half male, half female) completed the ANT while in an MRI scanner. Since many neuroimaging studies had looked at the brain areas that ‘light up’ during only 1 of 3 ANT components, these researchers wanted to look at every components’ associated brain activity in one study. Behaviorally, they found the usual results: no cues produced slower RTs than center cues, center cues produced slower RTs than spatial cues, and incongruent ‘flanking arrows’ produced slower RTs than congruent ones. There were no significant correlations between attention component scores (alerting, orienting, and conflict).

This is what participants viewed as they were performing the Attentional Network Task (ANT).

During the alerting component (a central cue indicates the target is coming), there was activation in the fronto-parietal cortex and the thalamus. The superior colliculus (involved in shifting gaze in the startle response) and the right temporal parietal junction were activated as well. Then, for the orienting component (a cue indicates where the target will be), the left and right parietal lobes lit up, as did the precentral gyrus (by the frontal eye field). The authors noted that there’s consensus on the activation prefrontal and parietal areas during orienting attention. Finally, for the executive/conflict component (the target is accompanied with flanking arrows), there was activity in the anterior cingulate plus the right and left frontal area, and the left and right fusiform gyrus. The anterior cingulate cortex has been demonstrated previously to be involved in conflict resolution (pay attention to one stimulus ignore another).

One of the main findings of this study was that these three facets of attention were activated in pretty independent brain regions. There were some notable exceptions, like the thalamus and the left fusiform gyrus were activated during both conflict and orienting, as were the left superior prefrontal gyrus and both the left and right fuisform gyrus. Overall though, this evidence suggests that directed attention activates generally independent regions of the brain. We can couple this with the evidence that performance on cognitive tasks that require directed attention are improved in ‘natural’ settings as opposed to urban settings, and this is associated with the anterior cingulate cortex and the left and right frontal cortices. Nothing suggests that other parts of the brain aren’t activated ever, at all, or even that other attention components of the ANT aren’t functionally involved in directed attention. However, it is quite likely that ‘natural’ settings can measurably affect our cognitive functioning, and we can map these effects at the level of the brain.